The present invention relates to a composite switch which performs simultaneous switching operation on a plurality of electrically independent circuits in various electronic apparatuses.
In general, a conventional composite switch has the structure of FIG. 11 which shows a cross sectional front view of the same. As shown in FIG. 11, the composite switch comprises two switches 321 and 322, which respectively have identical specifications and are disposed coaxially in two stages.
When the composite switch is used, for instance, for adjusting the output level of two circuits which work according to respective signals in the audio apparatus of a stereo system, the switching operation is performed by rotating one operating shaft 303.
On the other hand, when the audio apparatus is used as one circuit of a monaural system by operating the apparatus with one signal, the common contact point 341 of the switch 321 and the common contact point 342 of the switch 322 are short-circuited by using another switch 305 as shown in FIG. 12 so that the composite switch enters into a state for a switching operation on one circuit.
However, the above conventional composite switch is large in size. Also when the switch is used for switching operation on one circuit, the additional switch 305 has to be used, which requires large space in the audio apparatus. Also the switches disposed at two different positions have to be respectively operated.
The object of the present invention is to address the conventional problems and aims to provide a composite switch which is small in size and performs simultaneous switching operations on two independent circuits, and which also has a function for short-circuiting two switching structures in the composite switch when the composite switch is used for switching a operation on one circuit.
For realizing the above object, the composite switch of the present invention comprises:
(a) a first fixed contact unit and a second fixed contact unit disposed on the surface of a substrate in such a manner as to be symmetrical about a reference line which is perpendicular to the surface of the substrate,
(b) a first rotating contact unit which contacts with the first fixed contact unit or the second fixed contact unit, and a second rotating contact unit which contacts with the second fixed contact unit or the first fixed contact unit, wherein both the first and second rotating contact units are respectively held by a rotating member which rotates on an axis along the reference line,
(c) a first facing contact leg electrically connected to the first rotating contact unit, and a second facing contact leg electrically connected to the second rotating contact unit, wherein the first and the second facing contact legs are disposed in such a manner as to face each other across the reference line,
(d) a central movable contact member which is movable along the reference line into a state of electrical connection with the first and the second facing contact legs or into a state of electrical disconnection from the first and the second facing contact legs, and
(e) one or two operating shafts for rotating the rotating member and moving the central movable contact member along the reference line.
The above structure enables a reduction in size of a composite switch which performs simultaneous switching operations on two independent circuits and has a function for short-circuiting two switching structures in the composite switch for a switching operation on one circuit.